Analytic energy gradient of excited electronic state within TDDFT/MMpol framework: Benchmark tests and parallel implementation

作者：Zeng, Qiao^*; Liang, WanZhen

来源：Journal of Chemical Physics, 2015, 143(13): 134104.

DOI：10.1063/1.4931734

• DENSITY-FUNCTIONAL THEORY
• CONTINUUM SOLVATION MODELS
• INTERMOLECULAR POTENTIAL FUNCTION
• TAMM-DANCOFF APPROXIMATION
• MOLECULAR-ORBITAL METHODS
• LINEAR-RESPONSE METHODS
• GAUSSIAN-TYPE BASIS
• EXCITATION-ENERGIES
• Q-CHEM
• GEOMETRY OPTIMIZATIONS

The time-dependent density functional theory (TDDFT) has become the most popular method to calculate the electronic excitation energies, describe the excited-state properties, and perform the excited-state geometric optimization of medium and large-size molecules due to the implementation of analytic excited-state energy gradient and Hessian in many electronic structure software packages. To describe the molecules in condensed phase, one usually adopts the computationally efficient hybrid Quantum Mechanics/Molecular Mechanics (QM/MM) models. Here, we extend our previous work on the energy gradient of TDDFT/MM excited state to account for the mutual polarization effects between QM and MM regions, which is believed to hold a crucial position in the potential energy surface of molecular systems when the photoexcitation-induced charge rearrangement in the QM region is drastic. The implementation of a simple polarizable TDDFT/MM (TDDFT/MMpol) model in Q-Chem/CHARMM interface with both the linear response and the state-specific features has been realized. Several benchmark tests and preliminary applications are exhibited to confirm our implementation and assess the effects of different treatment of environmental polarization on the excited-state properties, and the efficiency of parallel implementation is demonstrated as well.

• 出版日期2015-10-7
• 单位厦门大学